Relay



Dec. 2, 1958 w. TANCRED RELAY Filed Sept. 24. 1954 ""lll//l UnitedStates Patent O f RELAY William L. Tancred, Hartford, Conn., assignor toThe W. N. Borg Corporation, Hartford, Conn., a corporation ofConnecticut Application September 24, 1954, Serial No. 458,165

Claims. (Cl. 317-197) This invention relates to an improvedelectromagnetic relay which has been previously disclosed in abandonedapplication Serial No. 259,065, tiled November 30, 1951.

Electrical and electronic equipment employed in many modern applicationsare quite often subjected to severe shock which may be caused by gunre,explosion, impact of projectiles, rapid changes in vehicle velocity, andthe like. The forces created by these conditions necessarily result inconsiderable momentary acceleration of the framework of the equipmentthereby subjecting the components to a corresponding acceleration. Itcan be readily appreciated that for proper equipment operation, theindividual components must be designed so as not to effectuate falseoperation in response to the forces of acceleration. Additionally, thedesign of these reliably operating components should incorporate otherdesirable characteristics, such as miniaturization, eicient operation,and economy of manufacture.

A principal object of this invention is to provide an electromagneticrelay having effective safeguards against false contact operation causedby the forces of acceleration, and featuring a design which is highlysensi-tive and effective to actuate a relatively large number ofcontacts reliably in any relay position with a structure of miniaturedimensions and which can be economically manufactured.

Another object is to provide an electromagnetic relay design possessingthe foregoing characteristics and which may also Ibe readily alteredduring the manufacturing operation to produce relays having varieddegrees of contact actuating force.

As is well known in the art, the Ibasic relay structure comprises amovable armature associated with an electromagnet, or a plunger actingin conjunction with a solenoid. The armature or plunger is arranged toactuate suitable contacts in response to the application of anenergizing current. When such a relay structure is undergoingsubstantial acceleration, the armature or plunger, while being subjectedto a relative motion restraining force such as that of a spring or thelike, may, due to inertia, fail to accelerate as rapidly as the relayframework and to move correspondingly with the remaining portion of therelay. This relative movement tends to actuate the relay and mayactually do so under severe conditions thereby producing false contactoperation.

Relays have heretofore been proposed having structural arrangementsdevised to safeguard against false contact operation caused by theforces of acceleration. One such structure features a plurality ofplunger or core members positioned within a solenoid such that contactoperation is effected only by movement of the core members in reversedirections relative to one another. In the main, such relative reversemotion of the core members cannot be produced by the usual acceleratingforces to which electrical and electronic equipments are subjected.

Other relay arrangements of the prior art have em- 2,863,103 PatentedDec. 2, 1958 ice ployed a balanced armature rotatably pivoted within asolenoid. Inasmuch as the forces of acceleration apply equal andopposing torques to each of the balanced armature sections oppositelydisposed with respect to the pivot, the armature cannot be rotated toproduce false contact operation. Prior art relays embodying this designhave not, however, attained optimum results with respect to relaysensitivity, damping control over the contact operation,miniaturization, and economy and simplicity of structure.

Accordingly, a preferred embodiment of the relay structure of thisinvention features advantageous improvements in the basic relaystructure employing a rotatably balanced armature in conjunction with anactuating solenoid. In particular, there is positioned at eachend of theactuating solenoid, a magnetic core each having a body portion fromwhich a relatively ilat pole piece projects into the centermost portionof the solenoid. The faces of both pole pieces are closely spaced withrespect to one another, and may overlap if contact damping is required.A balanced armature having a pair of relatively flat wing portions ispivotally positioned in the space gap between the pole pieces on a shaftsupported at the terminal ends thereof by the core members. The armatureis aligned with respect to its shaft support such that armature rotationoccurs in a plane which is perpendicular to the longitudinal axis of thesolenoid. This particular disposition of the rotating armature withinthe centermost portion of the solenoid and between the interveuing spacegap of the pole pieces provides for optimum sensitivity and contactactuating torque. These advantages occur because the intensity of themagnetic iield is greatest at the center of the solenoid, and alsobecause a minimum of magnetic reluctance is established by therelatively close magnetic coupling of the armature between therelatively large faces of the sandwiching pole pieces.

Another feature of the operation of the foregoing relay structure isthat any desired damping of the armature movement can be readilyobtained by lengthening or shortening the pole pieces relative to thecenter plane for the solenoid. That is, if the pole pieces areconstructed so as to overlap whereby each pole piece contains surfaceportions on both sides of the center plane, armature rotation can beeffectively dampened. Likewise, shortening the pole pieces so that theydo not project past the center plane produces a greater rotatable speed,and a distinctively sharper action opposite to damping.

The relay of this invention may also be effectively mniaturized becausesubstantially all of the contact driving structure is positioned withinthe solenoid; therefore, for any specified relay volume, an increasedcontact load may be actuated thereby. The contacts are actuated by aterminal portion of the armature support rod which projects out of thesolenoid such that a rotating torque is made available to actuate thecontact load. In a rst preferred embodiment, a spring is coupled to theprojecting portion of the rod so as to spring bias the armature andassociated contacts to the required non-operating position. nates thisbiasing spring and employs a pair of permanent magnetic discs positionedwithin the solenoid and magnetically coupled to the armature so as toposition the armature to the non-operate position. This latter biasingarrangement provides for further miniaturization. discs are positionedwithin similar polarities and will not lose magnetic eifectiveness sinceupon each energization the discs and poles will equalize in potential.

An alternative structural arrangement elimi.

These detailed reference is herein made to the accompanying drawingswherein:

Figure l is a central longitudinal sectional View of a preferredembodiment of the relay of this invention;

Figures 2, 3 and 4 are detail sectional views on the corresnondinglynumbered section lines of Figure l;

Figure 5 is an exploded perspective view of certain of the parts;

Figure 6 is a view similar to Figure 4 but showing a modification of thecontact load; and

Figure 7 is a View similar to Figure 2 but showing a modificationincorporating permanent magnet biasing of the armature.

Referring to the drawing, the relay shown therein cornprises acontrolling solenoid 10 supported on an inner tube 13 of non-magneticmaterial. This structure is encased within a suitable cylindricalenclosure 11 which may also be of non-magnetic material. A pair ofstationary cores 12 of magnetic material are secured within inner tube13 in an axially spaced relationship. The cores are separated one fromthe other by non-magnetic spacer 14 having a pair of end partitions 15which contact the inner faces of cores 12. Each of the cores is providedwith an eccentrically arranged pole piece 16 which extends lengthwisewithin tube 13 so that the common faces of pole pieces 16 are generallyparallel one to the other. These pole pieces may or may not extend pastthe center plane of the solenoid common with section line 2 2 for thereasons hereinafter set forth.

Shaft 17 extends through spacer 14 and rotatably supports magneticarmature 18 within the gap between pole pieces 16. Armature 18 comprisesa pair of oppositely directed, balanced wings 19, which during relayoperation contact the inner exposed faces of pole pieces 16 as is shownin the broken line position of Figure 2. In the relay non-operate orsolid line position shown in Figure 2, the opposite faces of wingportions 19 contact the inner faces of spacer 14. The terminal ends ofshaft 17 are loosely supported by core members 12.

Coil spring 20 is coupled to shaft 17 as shown in Figlures 1 and 4 so asto bias armature 18 to the solid line or non-operate position of Figure2. A first terminal portion of spring 20 is secured to fixed lug 21 andthe other terminal portion of spring 2t) is secured to shaft 17 at 22.When solenoid 10 is energized, armature 18 is rotated from the angularposition to which it is normally biased by spring 20 to the broken lineposition of Figure 2. This change in angular position may be employed toactuate the contact load as is shown, for example, in Figures 1 and 4.The rotation of armature 1-8 causes shaft 17 to drive contact arm 23until contacts 24 supported thereby engage with contacts 2S supported onterminals 26. These terminals extend through the end wall of insulatingcasing 27 which encloses the contact load whereby external connectionscan be made to the contacts. Cup-shaped mounting elements 28 couplescasing 27 to relay enclosure 11.

A normally-closed contact load is shown in Figure 6. In this modifiedarrangement, contact arm 23 and contacts 24 supported thereby arenormally held in engagement with contacts `31 by the biasing forceapplied by spring 20. The contacts are opened in response to theenergization of actuating solenoid 10.

An alternative arrangement for biasing armature 18 to the propernon-operate position is shown in Figure 7. In this modified arrangement,magnetic biasing is employed .in lieu of spring biasing. A pair ofpermanent magnet discs or buttons 32 are positioned in insulating spacer14 in such a manner as to normally hold the armature 12 out of contactwith the pole pieces 16. These magnets are ineffective, however, to sohold thearmature when the solenoid 1t) is energized.

Optimum relay sensitivity is attained by the foregoing structure whenpole pieces 16 extend to the center plane of the solenoid common withsection line 2 2 shown in Figure 1. If pole pieces 16 are constructed soas to overlap whereby each pole piece contains surface portions on bothsides of the center plane, armature rotation can be effectivelydampened. Counterwise, shortening the pole pieces so that they do notproject past the center plane intensities the armature movement.Accordingly, during the relay fabrication process relays characterizedby different degrees of armature damping or intensifying can be readilymanufactured by altering the length of the pole pieces the requiredamount with respect to the center plane for the solenoid to be used.

In View of the fact that the relay armature is positioned within thecentermost portion of the solenoid between the relatively close spacingof the extending pole pieces, optimum relay sensitivity is obtained witha structure which can be substantially miniaturized. It should be notedthat the relay motion mechanism is positioned in the main within thesolenoid and that only a terminal portion of the rotating shaft 17projects from the solenoid, thereby providing for an extremely compactrelay structure.

Further miniaturization is provided by employing the biasing arrangementshown in Figure 7 wherein spring 20, which is external to solenoid 10,is omitted and permanent magnets 32 positioned within the solenoidprovide for the requisite biasing force. The foregoing structurerepresents optimum economy in the use of component space and therefo-rethe design is adaptable for use in equipments having stringent volumerequirements.

It is to be understood that the above described arrangements areillustrative of the application of the principle of this invention.Numerous arrangements may be devised by those skilled in the art withoutdeparting from the scope of the invention.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. An electromagnetic relay comprising an actuating solenoid having asubstantially linear axis, a pair of axially spaced magnetic coresrigidly fixed within said solenoid, a relatively long and narrow polepiece projecting from the inner face of each of said core members to atleast the center-most portion of said solenoid with the inner pole facesthereof lying generally in parallel planes and being displaced in theseplanes with no more than a portion Iof the faces of each pole pieceoverlapping with respect to one another, a non-magnetic spacerseparating said cores one from the other and holding said pole pieces inthe afore-mentioned position, a rotatable shaft aligned with thelongitudinal axis of said solenoid and loosely supported by said coremembers and passing through said spacer and one of said core members, abalanced armature having equal depending wings rotatably positioned onsaid shaft in the space gap between said pole pieces, a bias springcoupled to the end of said shaft projecting through said core member andforcing said armature wings to contact said spacer, a contact armrigidly coupled to the projecting end of said shaft and actuating acontact load when said solenoid is energized thereby driving saidarmature in opposition to the force of said spring bias until saidarmature wings contact the faces of said pole pieces.

2. An electromagnetic relay comprising an actuating solenoid having asubstantially linear axis, a pair of axially spaced magnetic coresrigidly fixed within said solenoid, a relatively long and narrow polepiece projecting from the inner face of each of said core members to atleast the centermost portion of said solenoid with the inner pole facesthereof lying generally in parallel planes and being displaced in theseplanes with no more than a portion of the faces of each pole pieceoverlapping with respect to one another, a non-magnetic spacerseparating said cores one from the other and holding said pole pieces inthe aforementioned position, a rotatable shaft aligned with thelongitudinal axis of said solenoid and loosely supported by .said coremembers and passing through said spacer and one of said core members, abalanced armature having equal depending wings rotatably positioned onsaid shaft in the space gap between said pole pieces, a bias springcoupled to the end of said shaft projecting through said core member andforcing said armature wings to Contact said spacer, and a contact loadcoupled to the projecting end of said shaft and being actuated inresponse to the energization of said solenoid whereby said armature isdriven in opposition to the force of said spring bias until saidarmature wings contact the faces of said pole pieces.

3. An electromagnetic relay comprising an actuating solenoid having asubstantially linear axis, a pair of axially spaced magnetic coresrigidly xed within said solenoid, a finger-like pole piece projectingfrom the inner face of each of said core members to at least the centerportion of said solenoid, a rotatable shaft aligned with thelongitudinal axis of said solenoid and loosely supported by said coremembers and passing through one of said core members, a balancedarmature having equal depending Wings rotatably positioned on said shaftin the space gap between said pole pieces, means biasing said armatureto the non-operate position wherein said armature wings are separatedfrom said pole pieces, and a contact load rigidly coupled to theprojecting end of said shaft and being actuated in response to theenergization of said solenoid whereby said armature is driven inopposition to said bias until said armature Wings contact the faces ofsaid pole pieces.

4. An electromagnetic relay comprising an actuating solenoid having asubstantially linear axis, a pair of axially spaced magnetic coresrigidly fixed within said solenoid, a iinger-like pole piece projectingfrom the inner face of each of said core members toward the centerportion of said solenoid, a non-magnetic spacer positioned within saidsolenoid and separating said cores one from the other, a rotatable shaftaligned with the longitudinal axis of said solenoid and looselysupported by said core members and passing through said spacer and oneof said core members, a balanced armature having equal depending wingsrotatably positioned on said shaft in the space gap between said polepieces, means biasing said armature to the non-operate position whereinsaid armature wings contact said spacer, a contact load rigidly coupledto the projecting end of said shaft and being actuated in response tothe energization of said solenoid whereby said armature is driven inopposition to said bias until Said armature wings contact the faces ofsaid pole pieces, and said bias means including a pair of permanentmagnets positioned in the faces of said spacer which are contacted bysaid armature in the relay non-operative position.

5. The electromagnetic relay of claim 4 wherein said finger-like polepieces extend to at least the center plane for the solenoid wherebycontact `damping is effected.

References Cited in the tile of this patent UNITED STATES PATENTS2,353,756 Price July 18, 1944 2,364,656 Price Dec. 12, 1944 2,563,271Price Aug. 7, 1951 2,767,357 Naybor Oct. 16, 1956

